TABLE 4.
Kinetic parameters of OXAVL02 and OXAVL06 beta-lactamases in 25 mM HEPES pH 7.5 + 50 mM NaCarbonatea
| Antibiotics | OXAVL02 |
OXAVL06 |
||||
|---|---|---|---|---|---|---|
| Kcat (s−1) | Km (μM) | Kcat/Km (μM−1s−1) | Kcat (s−1) | Km (μM) | Kcat/Km (μM−1s−1) | |
| Ampicillin | 20 ± 2 | 380 ± 10 | 0.055 ± 0.007 | 530 ± 30 | 270 ± 20 | 2 ± 0.3 |
| Carbenicillin | 22 ± 1 | 400 ± 20 | 0.055 ± 0.005 | 380 ± 20 | 1400 ± 200 | 0.25 ± 0.05 |
| Piperacillin | 3 ± 0.02 | 850 ± 30 | 0.0055 ± 0.0003 | NH | NH | NH |
| Oxacillin | 1 ± 0.05 | 690 ± 40 | 0.0015 ± 0.0002 | 90 ± 5 | 160 ± 20 | 0.56 ± 0.10 |
| Cephaloridine | >12.5 | >400 | 0.030 ± 0.005 | 24 ± 3 | 90 ± 10 | 0.26 ± 0.06 |
| Nitrocefin | Product Inhibition | 350 ± 30 | 20 ± 0.5 | 17.5 ± 2 | ||
| Imipenem | 9 ± 1 | 550 ± 50 | 0.016 ± 0.002 | 0.9 ± 0.05 | 0.4 ± 0.05 | 2.5 ± 0.03 |
| Meropenem | 0.3 ± 0.05 | 6 ± 0.2 | 0.05 ± 0.01 | NH | NH | NH |
a
NH, no hydrolysis. Each kinetic value is the mean and standard deviation of three different measurements.